DPF – DIESEL PARTICULATE FILTER

To make cars with diesel engines more environmentally friendly, Diesel Particulate Filters (DPF) or Antiparty Filters (FAP) have been implemented in addition to the EGR valve (Exhaust Gas Recirculation), together they achieve a greater cleanliness in the gases that are expelled from these automobiles.

What is and what it’s for the DPF of a car?

A DPF (Diesel Particulate Filter) or Diesel Particle Filter is a device or system that is placed in the exhaust pipe of the car and serves to trap in its porous walls the soot generated by diesel engine gases. We can say that it is a kind of sponge, which absorbs all this dirt so that it does not reach the atmosphere.

In tests carried out to the DPF it has been verified that it can retain up to 85% of soot particles and in some cases up to 100%.

How does the DPF or FAP particle filter work?

The DPF or filter does its job in line with the rest of the car, retaining soot particles or pollutants that are generated with driving. However, like any filter, when it is full inside, it requires a process to regenerate or cleanse itself. In DPF filters, this cleaning or regeneration can be done in two ways:

• Passive regeneration: It is carried out when driving on long journeys or motorways; when a sensor sends a signal to the engine to warn you that the filter is saturated and that you must increase the amount of fuel briefly, this will cause the gases exiting the propeller to do so at a higher temperature. In this way it is possible to burn all the particles of the filter automatically without the driver intervening.
• Active regeneration: this is usually done when the car is used more in cities or a short trip that is when the exhaust is not hot enough, it must be injected with additional fuel and does it just before an oxygen catalyst, or on the contrary it must be connected to an electric heater to be without movement.

Types of diesel particle filters

In general, there are two types of DPF filters:

• Particulate filters without additive: This is the most used and is placed very close to the engine of the car, behind the exhaust manifold and next to the turbo. As the exhaust gas path between the motor and the filter is short, this allows the temperature to be high enough to burn the particles.
• Particle filters with additive: These are less used by manufacturers. In this case, the filter is farther from the engine, so to achieve the high temperatures that are needed when burning the particles, an additive must be added to the diesel, which will be activated when connecting with the particles inside the filter. Therefore, it is important that the additive reservoir is full every certain time, around 100,000 km as average.

Problems and solutions of the Particle Filter

The problem or inconvenience that has occurred in the cars that use the DPF Particle Filters is that if they are often used in short distances or in cities, these routes can have a negative effect on the particulate filter.

The same thing usually happens if you interrupt more than three times the filter regeneration cycle that lasts approximately 15 to 20 minutes, during which the engine must not stop and must go at a speed higher than 70 km / h.

If these problems occur, it is very likely that the light will illuminate on the dashboard, which will tell the driver that they should be attacked as soon as possible.

To prevent these problems from occurring, it is necessary to take into account the following:

• It is advisable to leave roads every once in a while, at least every 1000 km, for about 30 minutes so that you can regenerate the filter and extend its useful life.
• Maintain the filter according to the manufacturer’s specifications.

Maintenance of the Particle Filter

DPF Particle Filters should be cleaned regularly, some people do it once a year, and however, it is advisable to do it more constantly to extend the filter’s useful life.

This maintenance must be carried out in workshops by professionals, since they guarantee that the DPF works like new. Some of the processes that they carry out are the following:

• Search for dirt concentrations.
• Wash it with water under pressure.
• Place the DPF in the digital temperature control oven.
• You must bake or heat the piece to more than 1000 degrees Celsius between 6 to 8 hours approximately.
• Verify that it is completely clean and place it back on the burner.